Wheeled jack



Dec. 16, 1941.

e. ou Yu-z WHEELED JACK 5 Shee'ts-Sheet 1 Filed 001:. 25; 1-938 INVENTORATTORNEY Dec. 16, 1941'. QUAYLE 2,266,398

. WHEELED JACK Filed Oct. 25, 1938 5 Sheets-Sheet 2 INVENTOR MBY WMATIORNEY' De. 16,1941; 6. QLIJAYLEI 2,266,398

WHEELED JACK Filed Oct. 25, 1938 S Sheets-Sheet 5 WWW -" INVENTOR I BY 547 ATTORNEY -G. QUAYLE WHEELED JACK Dec. 16, 1941.

5 Sheets-Sheet 4 Filed 001:. 25, 1938 M v INVENTOR BY z 4 404% ATTORNEYDec. 36, 1941. G. QUAYLE WHEELED JACK Filed Oct. 25, 1938 5 Sheets-Sheet5 ATTO'RNEY Patented Dec. 16, 1941 George Quayle, Philadelphia, Pa.,assignor Yale & Towne Manufacturing Company,

to The Stamford, Conn, a corporation of Connecticut Application October25, 1938, Serial No. 236,866

24 Claims.

This invention relates to a type of lifting ap paratus known in the artas a wheeled jack or dolly. I shall herein call it a wheeled jack.

A wheeled jack is a two-wheeled lifting device especially adapted forlifting one end of a semilive skid platform, that is, a skid platformhaving two wheels at one end and two legs at its other end. By liftingthat end of the skid platform which rests on legs, off said legs, and onto the wheels of the wheeled jack, the semi-live skid platform isconverted into a full live skid platform, or the equivalent of a fourwheel truck.

In my invention, I utilize a form of engaging means between the jack andthe skid platform which is well known in the art, that is, a trunnion onthe jack having a socket cooperable with a pin depending downwardly fromthe skid platform. My invention is equally useful should it be desired.to use a pin on the trunnion and a socket on the skid platform, as isdisclosed in some prior art constructions.

While I have indicated that the general type of structure disclosed byme is old in the art, I should like to point out generallyseveral-important advantages which are inherent in the structure which Ihave conceived and shall hereinafter disclose. Other advantages willappear as a study is made of the specification which follows. As afeature of my invention, I utilize a construction in which it isnecessary that the operator assume the full weight of the load on thewheeled jack as by lifting it somewhat beyond its elevated position,before he can lower the skid platform on to its legs. Moreover, therelease of the load is accomplished, preferably, solely through theoperation of a lifting handle, rather than through additional meansworking in conjunction with the lifting handle. In this way, I preventaccidental release of the lifting mechanism and the free swinging of thehandle through the application of the loadto the wheeled jack. Thosefamiliar with this art will fully appreciate the value of thisconstruction, eliminating as it does the flying handle hazard.

As a further feature of my invention, I utilize a lifting handle orlever which is spring balanced at all times so as to remain in avertical position withoutv any effort on the part of the operator. Thisis an extremely desirable construction, and has long been sought for inthe art. Moreover, the means whereby the balanced handle is obtained aresimple, and the spring whichis required to be used is enclosed so as topresent a very sightly appearance, and so as to be fully operation, allas will has a further function in that it holdsthe various I parts of myjack assembled and positioned for be described.

The most important feature of my invention is, however, the simplicityof the construction of my new wheeled jack, whereby I am able toobtaineasy lifting with complete safety, and whereby I am able tocontrol the load and to lower the same without operating any system ofcomplicated controls. p I 7 I consider my invention a distinct andvaluable contribution to the priorart and do not wish to be limited inmy patent monopoly to the specific structure I have shown, but ratherwish to be protected in the enjoyment of my patent monopoly against theutilization of various other structures which may be devised by thoseskilled in the art embodying the principles of my invention.

For a description. of the'structure I have devised, I shall refer to thedrawings wherein Fig. 1 is a view showing a skid platform elevated by mywheeled jack and ready for movement by the operator. Fig. 2 is a View ofmy wheeled jack separated from the skid platform and in normal restingposition on the floor. Fig. 3 illustrates the wheeled jack of myinvention in partial section about to be applied to the downwardlydepending pin of the skid platform. Fig. 4 illustrates the parts of Fig.3 in a slightly different position and with the weight of the skidplatform about to be assumed by the wheeled jack. Fig. 5 is a viewshowing the parts of Fig. 4 after the front end of the skid platform hasbeen lifted and after the handle has been elevated somewhat and intoposition to move the load. Fig. 6 illustrates the position of the partsWhen the liftin lever has been moved into a position to release thetrunnion locking mechanism so as to allow the lowering of the skidplatform. Fig. 7 is a view looking downwardly on my wheeled jack withthe tubular lifting lever shown in section. Figs. 8, 9 and 10 areperspective views of the parts forming my invention.

Referring now more specifically to the drawings and especially toFigsvl, 2 and 3, it will be noted that my wheeled jack or dollycooperates with a semilive skid platform l0 having rear wheels H andfront supporting legs l2. In Fig. 1 the skid platform is shown supportedat its forward end by the wheels of my wheeled jack, but in Fig. 3 theskid platform ID is shown supported by its legs l2. Depending downwardlyfrom the forward end of the skid platform is a pin l3 which is adaptedto enter the socket [4 of the trunnion protected from any damage. Mybalancing spring I5 of'my Wheeled jack. Through lifting of the trunnionI5, by means to be described below, the front end of the skid platformis elevated from the position of Fig. 3 to the position of Fig. 1.

The construction of my wheeled jack is best illustrated in Figs. 3, 8, 9and 10. There it will be noted that the wheels I8 support an axle I! onwhich is mounted the main frame I8, through bearing hubs IS. The mainframe of course occupies that portion of the axle which is between thetwo wheels I6.

Bearing hubs 28 on the main frame support trunnion shafts 2| extendingat each side from the trunnion I5, as is best illustrated in Fig. 10. Inthis way, the trunnion I5 is allowed to hang vertically from frame I8 atall times when free. A pair of gravity dogs 22, identical in function,are also pivotally mounted on the trunnion shafts 2|, their surfaces 23cooperating with surfaces 24 formed on gravity detent plates 25 whichare also freely mounted on the trunnion shafts 2I.

The two detent plates 25 are joined by a cross bar 25 preferably weldedto the two plates. An angle iron 2'! is welded to the side Plates of themain frame I8 and forms a leg on which the entire dolly may rest in amanner best illustrated in Fig. 2.

In Fig. 8, I show a handle frame 28 which through bearings 29 is mountedon that portion of the main shaft II lying between the two side platesof the main frame I8. The handle frame 28 has fixed thereto as bywelding or in any other preferred way, a tubular lifting lever 30 whichhas secured to its upper end a cross bar 3| forming a handle. Thelifting lever 33 acts to lift the trunnion I 5 and therefore the skidplatform,

when swung downwardly, as will be described presently.

Mounted on shaft I'I between the side plates comprising the handlecarrying frame 28, is a locking lever 32 having a locking hook portion33 and horizontally extending frame contacting surfaces 34. The end ofthe locking lever 32 opposite the hook portion 33 is designated byreference numeral 35, and is connected through a pin 35 with a verticalstrut member 31 terminating at 38 in a piston-like portion having a lug39. The piston-like portion 33 slides in the tubular lifting lever 38asis illustrated. Between thelug 39 on piston 38 and an abutment 48fixed nearthe upper end of lifting lever 38, there is mounted a spring4!. It is obvious that this spring tends to separate portion 35 of thelocking lever 32 from the handle 33. As a matter of fact, the operationof the spring 4'I will best be appreciated if it be considered that itsaction is the same as though a spring were inserted in the space 42 inFig. 3 between the tubular lever 38 and handle carrying frame 28 on theone side, and the main frame It and arm 35 of locking lever. 32 on theother side.

The surfaces '34 extending horizontally from the locking lever 32, bestillustrated in Fig. 8, are forced by the spring 4| against the lowerangular surfaces of the side plates of main frame I8, as is bestillustrated in Fig. 3, and tend to rotate frame I8 in a counterclockwise direction about the shaft I1. At the same time, of course, thelifting lever 30' and handle carrying frame 28 are being rotated by thespring 4| in a clockwise or upward direction. It is the function of thedogs 22 previously described, to prevent the collapse of the entireapparatus and to maintain the apparatus properly assembled andpositioned. For this purpose, the dogs 22 are equipped with notches 43which in the normal position of the parts, coact with lugs 44 of thehandle carrying frame 28 to maintain the frame and handle in theposition of Fig. 3, and with the space 42 between the handle carryingframe 28 and the main frame I8.

The lower end of trunnion I5 is formed with a locking nose 45 which isadapted to engage with the hook portion 33 of the locking lever 32 underconditions to be described presently. It will also be well to indicatethat the gravity detent plates 25 are formed with surfaces 45 whichcooperate with detent surfaces 41 of the locking lever 32, best shown inFig. 8, all for a purpose to be described presently.

I shall now refer to the series of Figs. 2, 3, 4, 5 and 6 to describeone complete lifting and lowering operation of my wheeled jack.Referring now to Fig. 2, it will be noted that the wheeled jack issupported through its wheels I6 and leg 2'! on the floor. The dogs 22cooperate with lugs 44 on the handle carrying frame 28 to maintain thehandle carrying frame and the main frame in the position of Fig. 2 andagainst collapse through the action of the handle balancing spring 4!.The trunnion I5 hangs in a substantially vertical position, and ofcourse the locking lever 32 is positioned with its surfaces 34 againstthe lower edges of the side plates of the main frame I8 by the pressureof the handle balancing spring 4|.

By swinging the tubular lifting lever 38 from its position of Fig. 2 toits position of Fig. 3, the trunnion I5 may be positioned with itssocket I4 directly under the pin I3 of the skid platform, as in Fig. 3.The parts of the wheeled jack remain, however, in the same relation asin Fig. 2, all through the action of the dogs 22 which maintain thehandle carrying frame 28 in somewhat spaced relation to the main frameI8, the space being shown and designated by reference numeral 42 in Fig.3.

Downward swinging of the lifting lever 38 to its position of Fig. 4moves the trunnion I5 against the surface 43 from which depends the pinI3 of the skid platform. Once this has been done, it will readily beappreciated that the trunnion I5 will accept the load on the skidplatform, and that it will thereafter be possible to rotate the handlecarrying frame 28 through downward pressure on the lifting lever 33 inopposition to the pressure of the handle balancing spring 4|. Thisbrings the parts into the position of Fig. 4 and releases the handlecarrying frame 28 from dogs 22 which dogs then drop by gravity untiltheir surfaces 23 contact the surfaces 24 of the gravity detent plates25. This is actually the position of the parts in Fig. 4. No lifting hastaken place. All that has happened is the compression of handlebalancing spring 4|, and the releasing of the lifting lever from dogs22.

The actual lifting of the skid platform by further downward swingingmovement of the lifting lever 38 is best illustrated in Fig. 5. There itwill be noted that the main frame I8 has been rotated to bring thetrunnion shafts H and the trunnion I5 into a position corresponding toan elevation of the front end of the skid platform I 0. The cam surface45a to the rear of the locking nose 45 of the trunnion I5, has, duringthis movement of the main frame I8, first contacted the cam surface 49of the locking lever 32 so as to cam the locking lever downwardlyagainst the force of the balancing spring 4i. As the hook portion 33 ofthe locking lever 32 then moved into a position opposite the lockingnose 45 of the trunnion l5, the locking-lever 32 moved under theinfluence of the spring 4i whereby to effect the engagement of thelocking nose 45 with hook 33, as is illustrated in Fig. 5.

With the parts in this position, it is obvious that the trunnion I5 islocked by the locking lever 32 relatively to the main frame l8 and theaxle i1, so that the main frame can no longer rotate relatively to thetrunnion l5. Since the trunnion of course cannot rotate due to theaction of pin 13, the skid platform I will be maintained in its elevatedposition supported by the wheels it of my wh'eeled jack. The liftinglever 30 and its carrying frame 28 may now be moved as to their positionof Fig. to transport the skid platform to any desired location, withoutany interference from dogs 22.

Should it now be desired to lower the load, it is of course necessary tofirst release the trunnion l5 from the locking lever 32 by the movementof the hook 33 of the locking lever 32 away from the nose 45 of thetrunnion. This is accomplished by the operator of the wheeled jackassuming the load by proper manipulation of the lifting lever. Therelease of the trunnion I5 is best illustrated in Fig. 6, wherein itwill be noted that the lifting lever 30 has moved the main frame l8about the axis of the axle I! to a position somewhat beyond the normalelevated position of Fig. 5.

Since during this movement of main frame IS the trunnion I5 is held bythe skid platform pin 13 against any rotary movement whatsoever, thefollowing action takes place: The cam surface 50 of the locking lever 32moves against the surface 45a of the trunnion as the locking lever 32moves with the main frame l8 to the position of Fig. 6, and the fixedtrunnion surface 45a forces the locking lever 32 out of locking relationto the trunnion and into a position wherein detent surfaces 41 of lever32 interlock with the surfaces 46 of the gravity detent plates 25. Thismovement of lever 32, of course, releases main frame l8 for movementrelatively to the trunnion l5. It should be noted also that the movementof the gravity plates 25 into the position of Fig. 6, that is, intocooperation with the detent surfaces 41 of lever 32, moves the dogs 22into position for cooperation with the lugs 44 of the handle carryingframe 28, all as is quite apparent.

If now the operator allows the lifting lever 30 to move upwardly, thedetent plates 25 will continue holding the locking lever 32 so that itslooking hook portion 33 will move past the locking nose 45 of thetrunnion without engaging it. This will allow a rotation of the mainframe l8 about the axle l1 and relatively to the trunnion l5 so as tolower the trunnion and place the load of the skid platform on its legsl2. At the same time, the dogs 22 will have dropped by gravity withtheir surfaces 23 against surfaces 24 of the detent plates 25. Thismoves the notches 43 of dogs 22 into cooperation with the lugs 44 ofthehandle carrying frame 28, as is seen in Fig. 6, so as to control thatframe.

When the skid platform has been positioned so as to be supported by itslegs I2, a further rotation of the handle carrying frame 28 and thelever 30 will bring the bar 26 connecting detent plates 25 against theflat surface 26a of the trunnion [5 so that the plates 25 are incapableof further rotation with the locking lever 32. A slight further movementof the locking lever 32 with the lifting lever 30 and frame l8, releasesthe locking lever from the detent plates 25, restoring the locking lever32 to its normal functioning position ofFigs. 2 and 3. 1

I believe that the simplicity of operation ofmy invention will now beapparent. It will also be apparent that many changes in actual structuremay be made without departing from the basic principles of mycontribution to the art.

I now claim: 7

1. In a combination of the class described, a frame mounted on a-wheelsupported shaft for rotation in the axis of said shaft, a liftingtrunnion pivoted on said frame, said trunnion being adapted forengagement with means on a skid platform to be lifted and to bemaintained by said means thereafter in a predetermined position, alocking lever pivoted relatively to said frame and adapted to lock saidframe relatively to said trunnion when said trunnion is in an elevatedposition whereby to lock said frame against reverse pivotal movement tolower said trunnion, a lifting lever for rotating said frame about saidaxis whereby to lift'said trunnion, and means actuated by rotation ofsaid frame somewhat beyond a position corresponding to full lifting ofsaid trunnion, for releasing said trunnion from said locking lever.

2. In a combination of the class described, a frame mounted on a wheelsupported shaft for rotation in the axis of said shaft, a liftingtrunnion pivoted on said frame, said trunnion being adapted forengagement with means on a skid platform to be lifted and. to bemaintained by said means thereafter in a predetermined position, alocking lever pivoted relatively to said frame and adapted to lock saidframe relatively to said trunnion when said trunnion is in an elevatedposition whereby to lock said frame against reverse pivotal movement tolower said trunnion, a lifting lever for rotating said frame about andmeans.

whereby application of lifting pressure by said lifting lever to movesaid frame and trunnion beyond the elevated position of said trunnionreleases said trunnion from said locking lever.

3. Ina combination of the class described, a frame mounted on a wheelsupported shaft for rotation in the axis of said shaft, a liftingtrunnion pivoted on said frame, said trunnion being adapted forengagement with means on a skid platform to be lifted and to bemaintained by said means thereafter in a predetermined position, alocking lever movable to lock said frame relatively to said trunnionwhen said trunnion is in an elevated position whereby to lock said frameagainst reverse pivotal movement to lower said trunnion, a lifting leverpivoted relatively to said frame and adapted to rotate said frame aboutsaid axis whereby to lift said trunnion, and a spring between saidlifting lever and said locking'lever tending to rotate said levers inopposite directions.

4. In a combination of the class described, a frame mounted on awheel's'upported shaft for rotation in the axis of said shaft, a liftingtrunnion pivoted on said frame, said trunnion being adapted forengagement with means on a skid platform to be lifted and to bemaintained by said means thereafter in 'a'predetermined position, alocking lever movable to lock said frame relatively to said trunnionwhen said trunnion is in an elevated position whereby to lock said frameagainst reverse pivotal movement to lower said trunnion, a lifting leverfor rotating said frame about said axis whereby to lift said trunnion, a

spring between said liftin'g'lever; and said locking lever tending torotate said levers in opposite directionsand a dog pivoted on said frameand @Q l il l l morall ii? 34 ift n l t l? 9 maintain said lifting leveragainst said rotation.

a I a eemb ne i a f e las descr be a fram mou te a whe l temm a t forreiatien n. the rt f s id haft. a l f ing r nn on r e ed on aid tramsseie meni e being adapted fo ee ae eieei w th mea s 01- k platform to belifted and to be maintained by s id mean h r after in a predeterminedposiion; i 1991i er, m v 2 9? said ra relati el t aid tr nn n en strunnion n an le at pos t on h 110 k sa frame. a a ns e erse q a m em no lower sai runn n a l f in eve f a n Said rame abou aid x s wh eby to te i trunni n a spr n betwee s d ng lev a Said locking lever tending torotate said levers in opp s ts d re ives m an ai o ki level pressing onsaid frame and thereby tending to impart rotation to said frame, andmeans between said lifting lever and said frame for limiting therelative movement between said lifting lever and said frame, wherebysaid spring holdssaid frame, locking lever and lifting lever in pred te-mined r la d etition Q. In a combination of the class described, aframe mounted on a Wheel supported shaft for otat qn t e axis of a a t fng t nion pivoted o said frame, said trunnion being adapted for engaement with means on a skid platfOl'm to be lifted and to be maintainedby said means thereafter in a predetermined posi tion, a locking levermovable to lock said frame relatively to said trunnion when saidtrunnion is in an elevated position whereby to lock said frame againstreverse pivotal movement to lower said trunnion, a lifting lever forrotating said frame about, said axis whereby to lift said trunnion,means for releasing said locking lever from said trunnion when saidtrunnion and frame are moved to a position slightly beyond the normallifted position of said trunnion, and means for thereafter maintainingsaid locking lever in releasing position until said trunnion and framemove to a lowered position.

'7. In a combination of the class described, a frame mounted on a wheelsupported shaft for rotation in the axis of said shaft, a liftingtrunnion pivoted on said frame, said trunnion being adapted forengagement with means on a skid platform to be lifted and to bemaintained by said means thereafter in a predetermined position, alocking lever movable relatively to said frame and adapted to lock saidframe relatively to said trunnion when said trunnion is in an elevatedposition whereby to lock said frame against pivotal movement to lowersaid trunnion, a lifting lever for rotating said frame about said axiswhereby to lift said trunnion, and means for releasing said lockinglever from said trunnion when said trunnion and frame are moved by saidlifting lever to a position slightly beyond the normal lifted positionof said trunnion and for thereafter maintaining said locking lever inreleasing position until said trunnion and frame move to a loweredposition.

8. In a combination of the class described, a frame mounted on a wheelsupported shaft for rotation in the axis of said shaft, a liftingtrunnion pivoted on said frame, said trunnion being adapted forengagement with means on a skid platform to be lifted and to bemaintained by said means thereafter in a predetermined position, alocking lever pivoted relatively to said frame and adapted to lock saidframe relatively to said trunnion when said trunnion in an elevatedposition whereby to lock said frame against pivotal movement to lowersaid trunnion, a lifting lever for rotating said frame about said axiswhereby to lift said trunnion, means for releasing said locking leverfrom said trunnion when said trunnion and frame are moved to a positionslightly beyond the normal lifted position of said trunnion, a detentadapted to hold said locking lever in releasing position thereafter toallow lowering movement of said frame and trunnion, and means for movingsaid detent out of holding position as said trunnion is lowered wherebyto restore said locking lever to its normal functioning position.

QQIn a combination of the class described, a frame mounted on a wheelsupported shaft for rotation in the axis of said shaft, a liftingtrunnion pivoted on said frame, said trunnion being adapted forengagement with means on a skid platform to be lifted and to bemaintained by said means thereafter in a predetermined posi: tion, alocking lever movable to lock said frame relatively to said trunnionwhen said frame ele-, vates ai r ni n t ro gh o at on on s ax a liftinglever for rotating said frame to lift said trunnion, and a surface ofsaid trunnion cooperable. with said looking lever to earn said leveroutof looking position when said frame and locking lever are rotated to aposition beyond the DQ tion corresponding to a normal elevation of saidtrunnion. v

10. In a combination of the glass described, a frame mounted on a wheelsupported shaft for rotation n h a is 'e said haft i in tru nion pivotedon said frame, said trunnion being adapted for engagement with means ona skid platform to be lifted whereby to be maintained by said meansthereafter in a' predetermined position, a locking lever movable tolock; said frame relatively to said trunnion as said frame elevates saidvertically maintained trunnion through rotation on its axis, the saidrotation of said fr m mo n a d o leve nt e k n r lation to saidtrunnion, a lifting lever for r0: tating said frame to lift saidtrunnion, a surv face of said trunnion cooperable with said look: inglever to cam said lever out of locking position when said frame and saidlocking lever are rotated to a position beyond the position corremndi ea n rma l a n f e runnion n a d nt wan ed a hol sa d 99. 9% lev r infireme r ea i res gr hereafte h eb to allow reverse rotation of saidframe to lower said trunnion. I

11, In a combination of the class described, a frame mounted on a wheelsupported shaft for rotation in the axis of saidshaft, alifting'trunnion pivoted on said frame, said trunnion being adapted forengagement with means on a skid platform to be lifted and to bemaintained by said means thereafter in a predetermined position, alocking lever movable to lock said frame relatively to said trunnion assaid frame elevates said vertically maintained trunnion through rotationon its axis, the said rotation moving said locking lever into lookingrelation to said trunnion, lifting lever for rotating said frame to liftsaid trunnion, a surface of said trunnion coopernble with said lockinglever to cam said lever out of locking position when said frame isrotated to a position beyond the position corre sponding to a normalelevation of said trunnion, a det t da d to o d aid lock n lever n trueie e e sin posi on the eaf r o. a l w reverse rotation of said fram tolower said trunnion, and means for cainin'ing said detent outer holdingrelation to saidlockingTlever'as. said trunnion is lowered whereby'torestore said'looking lever to its normal'functioning position.

12. In a combination ofthe class described, a frame mounted on a wheelsupported shaft for rotation in the axis of said shaft, a liftingtrunnion pivoted on said frame, said trunnion being adapted forengagement with means on a' skid platform to be lifted and to bemaintained by said means in a predetermined position, a locking leverpivoted relatively toi said frame, a lifting lever for rotating saidframe about its axis whereby to lift said trunnion, spring meanspressing said lifting and locking levers in opposite directions, saidlocking lever being adapted to lock said frame to said trunnion whensaid frame elevates said'vertically maintained trunnion through rotationon its axis, a dog pivoted on said frame and adapted to lock saidlifting lever against said spring pressed movement beyond apredetermined position allowing said lifting lever a slight amount offree rotation against said spring pressure prior to actuating saidframe,

the rotation of said lifting lever through said u distance against saidspring pressure and while said trunnion and frame are held by contactwith the means on the skid platform being sufficient to release thelever from said dog.

13. Ina combination-of the class described, a 1 i frame mounted on awheel supported shaft for rotation in the axis 'of said shaft, a liftingtrunnion pivoted on said frame, said trunnion being adapted forengagement with means on a skid platform to be liftedwhereby to bemaintained i by said means in a vertical position, a locking leverpivoted relatively to said frame, a lifting lever for rotating saidframe about its axis whereby to lift said trunnion,spring means pressingsaid lifting and locking levers in opposite directions, said lockinglever being adapted to lock said frame to said trunnion when said frameelevates said vertically maintained trunnion through rotation on itsaxis, a dog pivoted on said frame and adapted to look said lifting leveragainst said spring pressed movement beyond a predetermined position 1allowing said lifting lever a slight amount of free rotation againstsaid spring pressure prior to actuating said frame, the rotation of saidlifting lever through said distance against said spring pressure andwhile said trunnion and frame are held by contact with the means on theskid platform being suflicient to release the lever from said dog, asurface of said trunnion cooperable with said locking lever to cam saidlever out of locking position when said frame and said locking lever arerotated to a position beyond the position corresponding to a normalelevation of said trunnion, a detent adapted to hold said locking leverin trunnion releasing position whereby to allow reverse rotation of saidframe to lower said trunnion while also moving said dog into positionfor locking said lifting lever once again against spring pressedmovement beyond said predetermined position, and means for moving saiddetent out of holding relation to said locking lever as said trunnion islowered.

14. In a device of the class described, a pair of wheels and a shaftsupported thereby, a main frame rotatable about the axis of said shaft,a lifting trunnion pivoted on said frame and adapted to be lifted andlowered as said frame rotates on said axis, a lifting lever for rotatingsaid frame, a spring pressing said lifting lever upwardly and in anon-lifting direction relatively to said frame,"and means between saidframe and lifting lever for locking said lifting lever against saidmovement by said spring in a non-lifting direction while allowingrotation of said lifting lever in a downwardly or lifting directionrelativelyfto said frame. l v

15. In a device of the class described, a pair of wheels and a" shaftsupported thereby, a frame rotatable about the axis of said shaft, alifting trunnion pivoted on said frame and adapted to be lifted andlowered as said frame rotates on said axis, a lifting lever for rotatingsaid frame, a spring pressing said lifting lever upwardly and in anon-lifting direction relatively to said frame,

a dog carried by said main frame for locking said lifting lever againstsaid spring pressed movement while allowing free rotation of saidlifting lever in a-downwardly or lifting direction relatively to saidframe, and a foot on-said frame for supporting it and its trunnion andsaid lifting lever in a resting-position. v I

16. In a device of the class-described, a pair of wheels and a shaftsupported thereby, a frame rotatable about the axis of said shaft, alifting trunnion pivoted on said frame and adapted to be lifted andlowered as said frame rotates on said axis, aliftinglever adapted torotate said frame about said axis whereby to lift said'trunnion, abalancing spring pressing said lifting lever upwardly and in anon-lifting direction relatively tosaidframe, anda gravity dog carriedby said frame for locking said lifting lever against said spring pressedmovement beyond a predetermined position relatively to said frame, whileallowing free rotation of said lifting lever in a'downwardly or liftingdirection relatively to said frame. l 7

17. In a combination of the class described, a frame mounted on a wheelsupported shaft for r0- tation in the axis of said shaft, a liftingtrunnion pivoted on said frame, said trunnion being adapted forengagement with means on askid platform to be lifted and to bemaintained. by said means thereafter in a predetermined position, alocking lever pivoted relatively to said frame and adapted to lock saidframe relatively to said trunnion when said trunnion is in-an elevatedposition whereby to lock said frame against reverse pivotal movement tolower said trunnion, a lifting lever of tubular form for rotatg saidframe about said axis whereby. to lift said trunnion, a spring in saidtubularlifting lever, and means for securing said spring relatively'tosaid frame for pressing said tubular handle and said frame in. oppositedirections.

18. In a combination of the class described, a frame mounted on awheelsupported shaft for rotation in the axis of said shaft, a liftingtrunnion pivoted on said frame, said trunnion being adapted forengagement with means on a skid platform to be lifted and to bemaintained by said means thereafter in a predetermined position, alocking lever pivoted relatively to said frame and adapted to lock saidframe relatively to said trunnion when said trunnion is in an elevatedposition whereby to lock said frame against reverse pivotal movement tolower said trunnion, a lifting lever of tubular form for rotating saidframe about said axis whereby to lift said trunnion, a spring in saidtubular lifting lever, means whereby said spring is secured at its lowerend to said locking lever, whereby said spring tends to swing saidtubular handle upwardly relatively to said frame while simultaneoiis'lypressing said locking lever in a locking dir'eetioh. V i

i 19. In a 'coinbin'ationof the class de's'cribeda frame inbi'inted on awheel supported shaft for rotation the axis of "said shaft, a liftingtrun' man pivoted on said frame, said trunnion being adapted forengagement with means on a skid platferrn to b'e lifted and to bemaintained by said means thereafter in a predetermined position, alocking means for locking said frame relativelyto said trunnion whensaid trunnion is in an elevated pp saian whereby to l oek said frameagainst revi se pivotal movement to lower 's'aid PI 'llIQfliQIi, a Vlifting lever jfor rotating said frame about said axis wherebyto liftsaid trunnion, and means actuated by rotation of said frame seine- Wh fiybnd @P dti flQ I Pd Qfi 56 l l ing of said trunnion for releasing saidtrunnion om sa oc n me p, 20; In a combination of theclass described, aframe mounted on a wheel supportedshaft for rotation in the axis of saidshafta lifting trunnion piyoted on said frame, said trunnion beingadapted for engagement with means ona siiid 'platforrnto belifted and tobe maintained bysaid means thereaftenin a predetermined position,locking means for locking said frame relatively to said trunnion whensaid trunnion is in an ele: vated position, whereby to lock said frameagainst reverse pivotalmovement to lower said trunnion, a liftingleverfor rotating said frame about said axis whereby to lift saidtrunnion, means actuated by rotation of said frame somewhat beyond aposition correspondingto full lifting of said trunnion for releasingsaid trunnion from said locking means, and means for holding saidlooking means out of locking position until said trunnion is lowered.

21'. In a combination of the class described, a frame mounted on a wheelsupported shaft for rotation in the axis of said shaft, a liftingtrunnion pivoted on said frame, said trunnion being adapted forengagement with means on a skid platform to be lifted and to bemaintained by said means thereafter in a predetermined position, alocking lever pivoted relatively to said frame and adapted to lock saidframe relatively to said trunnion when said trunnion is in an elevatedposition whereby to lock said frame against pivotal movement to lowersaid trunnion; a lifting lever for rotating said frame aboutsaid axiswhereby to lift said trunnion, means for releasing said locking leverfrom said trunnion when said trunnion and frame are moved by saidlifting lever to a position slightly beyond the normal lifted positionof said trunnion, means for thereafter maintaining said locking lever inreleasing position until said trunnion and frame move to "a loweredposition, and means for mov'- ing' saidlast means out of maintainingposition when said trunnion is lowered.

22., In a device of the class described, a pair of wheels and a shaftsupported thereby, a main frame 'rgitatable about the axis of saidshaft, a lifting" t unnion pivoted on said frame and adapted to belifted and lowered as said frame rotates 'on said axis, a lifting leverfor rotating said frame, a spring pressing said lifting lever upwardlyand in a scanning direction relatively to said frame, a do'g for lockingsaid lifting lever against rotation bysaid spring relatively tosaidfr'ame beyond a predetermined position, said lifting lever movingagainst said spring pressure relatively to said frame when said frame isheld against movement with said lever as when said trunnion is nengagement with a load to be lifted, said relati" movement between thelifting lever the frame releasing the lifting lever from said dog. a

23. In a device of the lass described, a pair of wheels and shaftsiipportd thereby, a main framerotatable about the axis of said shaft, alifting trunnion pivoted on said frame and adapted to be lifted andlowered as said frame rotates on said axis, a lifting iey -ior rotatingsaid frame, a spring pressing said liftinglever upwardly and in anon-lifting direction relatively to said frame, and means between saidframe and lifting lever for locking said lifting lever against saidmovement by said spring in a non-lifting direction while allowingrotation of said lifting lever in a downwardly or lifting directionrelatively to said frame when said frame is held against movement withsaid lever as when said trunnion is in engagement with a load to belifted.

24. In a device of the class described, a pair of wheels and a shaftsupported thereby, a main frame rotatable about the axis of said shaft,a lifting trunnion pivoted on said frame and adapted to be lifted andlowered as said frame rotates on said axis, a lifting lever for rotatingsaid frame, a spring pressing said lifting lever upwardly and in anon-lifting direction relatively to said frame, means between said frameand lifting lever for locking said lifting lever against 'said movementby said spring in a non-lifting direction while allowing rotation ofsaid lifting lever in a downwardly o'r lifting direction relatimely tosaid frame when said frame is held against movement with said lever aswhen said trunnion is in engagement with a load to be lifted, saidrelative movement between the liftiiig lever and said frame releasingsaid lifting lever from said means.

GEORGE QUAYLE.

